Java : File with Examples

File (Java SE 22 & JDK 22) with Examples.
You will find code examples on most File methods.

Warning :

The File class is a legacy API. It is recommended to use the newer APIs Path and Files instead.

Please see also : Don't use the legacy File class, use new I/O APIs instead

Summary

An abstract representation of file and directory pathnames.

Class diagram

Note :

Most of the code examples in this article are run on Windows. However, some of the code examples are run on Linux.

final var file = new File("R:\\java-work\\aaa.txt");
System.out.println(file); // R:\java-work\aaa.txt

System.out.println(file.exists()); // false

try (final var writer = new FileWriter(file)) {
    writer.write("abc");
    writer.write("XYZ");
}

System.out.println(file.exists()); // true
System.out.println(file.isFile()); // true
System.out.println(file.isDirectory()); // false

// --- PowerShell ---
//PS R:\java-work> ls -Name
//aaa.txt
//
//PS R:\java-work> cat aaa.txt
//abcdXYZ

Fields

static final String pathSeparator

The system-dependent path-separator character, represented as a string for convenience.

final var os = System.getProperty("os.name");
System.out.println(os); // Windows 10

System.out.println(File.pathSeparator); // ;
System.out.println(Arrays.toString(File.pathSeparator.getBytes())); // [59]

static final char pathSeparatorChar

The system-dependent path-separator character.

final var os = System.getProperty("os.name");
System.out.println(os); // Windows 10

System.out.println(File.pathSeparatorChar); // ;

final int c = File.pathSeparatorChar;
System.out.println(c); // 59

static final String separator

The system-dependent default name-separator character, represented as a string for convenience.

final var os = System.getProperty("os.name");
System.out.println(os); // Windows 10

System.out.println(File.separator); // \
System.out.println(Arrays.toString(File.separator.getBytes())); // [92]

static final char separatorChar

The system-dependent default name-separator character.

final var os = System.getProperty("os.name");
System.out.println(os); // Windows 10

System.out.println(File.separatorChar); // \

final int c = File.separatorChar;
System.out.println(c); // 92

Constructors

File (File parent, String child)

Creates a new File instance from a parent abstract pathname and a child pathname string.

final var parent = new File("R:\\java-work");
System.out.println(parent); // R:\java-work

final var file = new File(parent, "aaa.txt");
System.out.println(file); // R:\java-work\aaa.txt

System.out.println(file.exists()); // false

System.out.println(file.createNewFile()); // true
System.out.println(file.exists()); // true

File (String pathname)

Creates a new File instance by converting the given pathname string into an abstract pathname.

final var file = new File("R:\\java-work\\aaa.txt");
System.out.println(file); // R:\java-work\aaa.txt

System.out.println(file.exists()); // false

System.out.println(file.createNewFile()); // true
System.out.println(file.exists()); // true

File (String parent, String child)

Creates a new File instance from a parent pathname string and a child pathname string.

final var parent = "R:\\java-work";
System.out.println(parent); // R:\java-work

final var file = new File(parent, "aaa.txt");
System.out.println(file); // R:\java-work\aaa.txt

System.out.println(file.exists()); // false

System.out.println(file.createNewFile()); // true
System.out.println(file.exists()); // true

File (URI uri)

Creates a new File instance by converting the given file: URI into an abstract pathname.

final var uri = URI.create("file:///R:/java-work/aaa.txt");
System.out.println(uri); // file:///R:/java-work/aaa.txt

final var file = new File(uri);
System.out.println(file); // R:\java-work\aaa.txt

System.out.println(file.exists()); // false

System.out.println(file.createNewFile()); // true
System.out.println(file.exists()); // true

Methods

boolean canExecute ()

Tests whether the application can execute the file denoted by this abstract pathname.

// --- Linux Terminal ---
//$ touch sample1.sh
//$ ls -l sample1.sh
//-rw-rw-r-- 1 xxxx xxxx 0 ... sample1.sh

final var os = System.getProperty("os.name");
System.out.println(os); // Linux

final var file = new File("sample1.sh");
System.out.println(file); // sample1.sh

System.out.println(file.canExecute()); // false
System.out.println(file.setExecutable(true)); // true

System.out.println(file.canExecute()); // true

// --- Linux Terminal ---
//$ ls -l sample1.sh
//-rwxrw-r-- 1 xxxx xxxx 0 ... sample1.sh

// --- Linux Terminal ---
//$ touch sample2.sh
//$ ls -l sample2.sh
//-rw-rw-r-- 1 xxxx xxxx 0 ... sample2.sh

final var file = new File("sample2.sh");
System.out.println(file); // sample2.sh

System.out.println(file.canExecute()); // false
System.out.println(file.setExecutable(true, false)); // true

System.out.println(file.canExecute()); // true

// --- Linux Terminal ---
//$ ls -l sample2.sh
//-rwxrwxr-x 1 xxxx xxxx 0 ... sample2.sh

boolean canRead ()

Tests whether the application can read the file denoted by this abstract pathname.

// --- Linux Terminal ---
//$ touch sample1.txt
//$ ls -l sample1.txt
//-rw-rw-r-- 1 xxxx xxxx 0 ... sample1.txt

final var os = System.getProperty("os.name");
System.out.println(os); // Linux

final var file = new File("sample1.txt");
System.out.println(file); // sample1.txt

System.out.println(file.canRead()); // true
System.out.println(file.setReadable(false)); // true

System.out.println(file.canRead()); // false

// --- Linux Terminal ---
//$ ls -l sample1.txt
//--w-rw-r-- 1 xxxx xxxx 0 ... sample1.txt

// --- Linux Terminal ---
//$ touch sample2.txt
//$ ls -l sample2.txt
//-rw-rw-r-- 1 xxxx xxxx 0 ... sample2.txt

final var file = new File("sample2.txt");
System.out.println(file); // sample2.txt

System.out.println(file.canRead()); // true
System.out.println(file.setReadable(false, false)); // true

System.out.println(file.canRead()); // false

// --- Linux Terminal ---
//$ ls -l sample2.txt
//--w--w---- 1 xxxx xxxx 0 ... sample2.txt

boolean canWrite ()

Tests whether the application can modify the file denoted by this abstract pathname.

// --- Linux Terminal ---
//$ touch sample1.txt
//$ ls -l sample1.txt
//-rw-rw-r-- 1 xxxx xxxx 0 ... sample1.txt

final var os = System.getProperty("os.name");
System.out.println(os); // Linux

final var file = new File("sample1.txt");
System.out.println(file); // sample1.txt

System.out.println(file.canWrite()); // true
System.out.println(file.setWritable(false)); // true

System.out.println(file.canWrite()); // false

// --- Linux Terminal ---
//$ ls -l sample1.txt
//-r--rw-r-- 1 xxxx xxxx 0 ... sample1.txt

// --- Linux Terminal ---
//$ touch sample2.txt
//$ ls -l sample2.txt
//-rw-rw-r-- 1 xxxx xxxx 0 ... sample2.txt

final var file = new File("sample2.txt");
System.out.println(file); // sample2.txt

System.out.println(file.canWrite()); // true
System.out.println(file.setWritable(false, false)); // true

System.out.println(file.canWrite()); // false

// --- Linux Terminal ---
//$ ls -l sample2.txt
//-r--r--r-- 1 xxxx xxxx 0 ... sample2.txt

int compareTo (File pathname)

Compares two abstract pathnames lexicographically.

final var os = System.getProperty("os.name");
System.out.println(os); // Windows 10

// A path name on Windows is not case-sensitive.
final var file1 = new File("aaa.txt");
final var file2 = new File("AAA.txt");

System.out.println(file1); // aaa.txt
System.out.println(file2); // AAA.txt
System.out.println(file1.compareTo(file2)); // 0

final var file1 = new File("aaa.txt");
final var file2 = new File("bbb.txt");

System.out.println(file1); // aaa.txt
System.out.println(file2); // bbb.txt
System.out.println(file1.compareTo(file2)); // -1
System.out.println(file2.compareTo(file1)); // 1

boolean createNewFile ()

Atomically creates a new, empty file named by this abstract pathname if and only if a file with this name does not yet exist.

final var file = new File("R:\\java-work\\aaa.txt");
System.out.println(file); // R:\java-work\aaa.txt

System.out.println(file.exists()); // false
System.out.println(file.createNewFile()); // true

System.out.println(file.exists()); // true
System.out.println(file.createNewFile()); // false

static File createTempFile (String prefix, String suffix)

Creates an empty file in the default temporary-file directory, using the given prefix and suffix to generate its name.

final var ret1 = File.createTempFile("prefix-", "-suffix");

// C:\Users\xxx\AppData\Local\Temp\prefix-1788635824849128964-suffix
System.out.println(ret1);

final var ret2 = File.createTempFile("abcd-", ".txt");

// C:\Users\xxx\AppData\Local\Temp\abcd-2471973508160575501.txt
System.out.println(ret2);

final var ret3 = File.createTempFile("prefix-", null);

// C:\Users\xxx\AppData\Local\Temp\prefix-4955106351488410780.tmp
System.out.println(ret3);

static File createTempFile (String prefix, String suffix, File directory)

Creates a new empty file in the specified directory, using the given prefix and suffix strings to generate its name.

final var dir = new File("R:\\java-work");
System.out.println(dir); // R:\java-work
System.out.println(dir.isDirectory()); // true

final var ret1 = File.createTempFile("prefix-", "-suffix", dir);
System.out.println(ret1); // R:\java-work\prefix-11985693266629058833-suffix

final var ret2 = File.createTempFile("abcd-", ".txt", dir);
System.out.println(ret2); // R:\java-work\abcd-17241334720235449415.txt

final var ret3 = File.createTempFile("prefix-", null, dir);
System.out.println(ret3); // R:\java-work\prefix-16933306792652896919.tmp

boolean delete ()

Deletes the file or directory denoted by this abstract pathname.

final var file = new File("R:\\java-work\\aaa.txt");
System.out.println(file); // R:\java-work\aaa.txt

final var dir = new File("R:\\java-work\\dir");
System.out.println(dir); // R:\java-work\dir

System.out.println(file.createNewFile()); // true
System.out.println(dir.mkdir()); // true

// --- PowerShell ---
//PS R:\java-work> ls | Format-Table -Property Mode, Name
//
//Mode  Name
//----  ----
//d---- dir
//-a--- aaa.txt

System.out.println(file.delete()); // true
System.out.println(file.exists()); // false

//PS R:\java-work> ls | Format-Table -Property Mode, Name
//
//Mode  Name
//----  ----
//d---- dir

System.out.println(dir.delete()); // true
System.out.println(dir.exists()); // false

// --- PowerShell ---
//PS R:\java-work> ls
//<No files / directories>

// --- PowerShell ---
//PS R:\java-work> tree /F
//...
//R:.
//└─dir
//        aaa.txt
//        bbb.txt

final var dir = new File("R:\\java-work\\dir");
System.out.println(dir); // R:\java-work\dir
System.out.println(dir.isDirectory()); // true

System.out.println(dir.delete()); // false

void deleteOnExit ()

Requests that the file or directory denoted by this abstract pathname be deleted when the virtual machine terminates.

public class Main {

    public static void main(String[] args) throws IOException {

        final var file = new File("sample.txt");
        System.out.println("file = " + file);

        System.out.println("file.exists = " + file.exists());

        file.deleteOnExit();
        System.out.println("deleteOnExit : OK!");

        System.out.println("file.exists = " + file.exists());
    }
}

// --- PowerShell ---
//PS R:\java-work> ls -Name
//Main.java
//sample.txt
//
//PS R:\java-work> java Main.java
//file = sample.txt
//file.exists = true
//deleteOnExit : OK!
//file.exists = true
//
//PS R:\java-work> ls -Name
//Main.java

boolean equals (Object obj)

Tests this abstract pathname for equality with the given object.

final var os = System.getProperty("os.name");
System.out.println(os); // Windows 10

// A path name on Windows is not case-sensitive.
final var file1 = new File("aaa.txt");
final var file2 = new File("AAA.txt");

System.out.println(file1); // aaa.txt
System.out.println(file2); // AAA.txt
System.out.println(file1.equals(file2)); // true

final var file1 = new File("aaa.txt");
final var file2 = new File("bbb.txt");

System.out.println(file1); // aaa.txt
System.out.println(file2); // bbb.txt
System.out.println(file1.equals(file2)); // false
System.out.println(file2.equals(file1)); // false

boolean exists ()

Tests whether the file or directory denoted by this abstract pathname exists.

final var file = new File("R:\\java-work\\aaa.txt");
System.out.println(file); // R:\java-work\aaa.txt

final var dir = new File("R:\\java-work\\dir");
System.out.println(dir); // R:\java-work\dir

final var nonExistentPath = new File("R:\\java-work\\xxx");
System.out.println(nonExistentPath); // R:\java-work\xxx

System.out.println(file.createNewFile()); // true
System.out.println(dir.mkdir()); // true

// --- PowerShell ---
//PS R:\java-work> ls | Format-Table -Property Mode, Name
//
//Mode  Name
//----  ----
//d---- dir
//-a--- aaa.txt

System.out.println(file.isFile()); // true
System.out.println(file.isDirectory()); // false
System.out.println(file.exists()); // true

System.out.println(dir.isFile()); // false
System.out.println(dir.isDirectory()); // true
System.out.println(dir.exists()); // true

System.out.println(nonExistentPath.isFile()); // false
System.out.println(nonExistentPath.isDirectory()); // false
System.out.println(nonExistentPath.exists()); // false

File getAbsoluteFile ()

Returns the absolute form of this abstract pathname.

public class Main {

    public static void main(String[] args) throws IOException {

        final var userDir = System.getProperty("user.dir");
        System.out.println("user.dir = " + userDir);

        {
            final var file = new File("aaa.txt");

            System.out.println("------");
            System.out.println("file = " + file);
            System.out.println("isAbsolute = " + file.isAbsolute());
            System.out.println("getAbsoluteFile = " + file.getAbsoluteFile());
            System.out.println("getAbsolutePath = " + file.getAbsolutePath());
        }
        {
            final var file = new File("R:\\java-work\\bbb.txt");

            System.out.println("------");
            System.out.println("file = " + file);
            System.out.println("isAbsolute = " + file.isAbsolute());
            System.out.println("getAbsoluteFile = " + file.getAbsoluteFile());
            System.out.println("getAbsolutePath = " + file.getAbsolutePath());
        }
    }
}

// --- PowerShell ---
//PS R:\java-work> java Main.java
//user.dir = R:\java-work
//------
//file = aaa.txt
//isAbsolute = false
//getAbsoluteFile = R:\java-work\aaa.txt
//getAbsolutePath = R:\java-work\aaa.txt
//------
//file = R:\java-work\bbb.txt
//isAbsolute = true
//getAbsoluteFile = R:\java-work\bbb.txt
//getAbsolutePath = R:\java-work\bbb.txt

String getAbsolutePath ()

Returns the absolute pathname string of this abstract pathname.

public class Main {

    public static void main(String[] args) throws IOException {

        final var userDir = System.getProperty("user.dir");
        System.out.println("user.dir = " + userDir);

        {
            final var file = new File("aaa.txt");

            System.out.println("------");
            System.out.println("file = " + file);
            System.out.println("isAbsolute = " + file.isAbsolute());
            System.out.println("getAbsoluteFile = " + file.getAbsoluteFile());
            System.out.println("getAbsolutePath = " + file.getAbsolutePath());
        }
        {
            final var file = new File("R:\\java-work\\bbb.txt");

            System.out.println("------");
            System.out.println("file = " + file);
            System.out.println("isAbsolute = " + file.isAbsolute());
            System.out.println("getAbsoluteFile = " + file.getAbsoluteFile());
            System.out.println("getAbsolutePath = " + file.getAbsolutePath());
        }
    }
}

// --- PowerShell ---
//PS R:\java-work> java Main.java
//user.dir = R:\java-work
//------
//file = aaa.txt
//isAbsolute = false
//getAbsoluteFile = R:\java-work\aaa.txt
//getAbsolutePath = R:\java-work\aaa.txt
//------
//file = R:\java-work\bbb.txt
//isAbsolute = true
//getAbsoluteFile = R:\java-work\bbb.txt
//getAbsolutePath = R:\java-work\bbb.txt

File getCanonicalFile ()

Returns the canonical form of this abstract pathname.

public class Main {

    public static void main(String[] args) throws IOException {

        final var userDir = System.getProperty("user.dir");
        System.out.println("user.dir = " + userDir);

        {
            final var file = new File("dir\\aaa.txt");

            System.out.println("------");
            System.out.println("file = " + file);
            System.out.println("getCanonicalFile = " + file.getCanonicalFile());
            System.out.println("getCanonicalPath = " + file.getCanonicalPath());
        }
        {
            final var file = new File("dir\\..\\bbb.txt");

            System.out.println("------");
            System.out.println("file = " + file);
            System.out.println("getCanonicalFile = " + file.getCanonicalFile());
            System.out.println("getCanonicalPath = " + file.getCanonicalPath());
        }
    }
}

// --- PowerShell ---
//PS R:\java-work> java Main.java
//user.dir = R:\java-work
//------
//file = dir\aaa.txt
//getCanonicalFile = R:\java-work\dir\aaa.txt
//getCanonicalPath = R:\java-work\dir\aaa.txt
//------
//file = dir\..\bbb.txt
//getCanonicalFile = R:\java-work\bbb.txt
//getCanonicalPath = R:\java-work\bbb.txt

String getCanonicalPath ()

Returns the canonical pathname string of this abstract pathname.

public class Main {

    public static void main(String[] args) throws IOException {

        final var userDir = System.getProperty("user.dir");
        System.out.println("user.dir = " + userDir);

        {
            final var file = new File("dir\\aaa.txt");

            System.out.println("------");
            System.out.println("file = " + file);
            System.out.println("getCanonicalFile = " + file.getCanonicalFile());
            System.out.println("getCanonicalPath = " + file.getCanonicalPath());
        }
        {
            final var file = new File("dir\\..\\bbb.txt");

            System.out.println("------");
            System.out.println("file = " + file);
            System.out.println("getCanonicalFile = " + file.getCanonicalFile());
            System.out.println("getCanonicalPath = " + file.getCanonicalPath());
        }
    }
}

// --- PowerShell ---
//PS R:\java-work> java Main.java
//user.dir = R:\java-work
//------
//file = dir\aaa.txt
//getCanonicalFile = R:\java-work\dir\aaa.txt
//getCanonicalPath = R:\java-work\dir\aaa.txt
//------
//file = dir\..\bbb.txt
//getCanonicalFile = R:\java-work\bbb.txt
//getCanonicalPath = R:\java-work\bbb.txt

long getFreeSpace ()

Returns the number of unallocated bytes in the partition named by this abstract path name.

final var file = new File("D:");
System.out.println(file); // D:

// --- PowerShell ---
//PS R:\java-work> Get-PSDrive D
//
//Name           Used (GB)     Free (GB) Provider      Root ...
//----           ---------     --------- --------      ---- ...
//D                1665.41        197.48 FileSystem    D:\  ...

System.out.println(file.getTotalSpace()); // 2000263573504
System.out.println(file.getFreeSpace()); // 212039778304
System.out.println(file.getUsableSpace()); // 212039778304

String getName ()

Returns the name of the file or directory denoted by this abstract pathname.

final var file = new File("dir1\\dir2\\aaa.txt");

System.out.println(file.getPath()); // dir1\dir2\aaa.txt
System.out.println(file.getName()); // aaa.txt
System.out.println(file.getParent()); // dir1\dir2

String getParent ()

Returns the pathname string of this abstract pathname's parent, or null if this pathname does not name a parent directory.

final var file = new File("dir1\\dir2\\aaa.txt");

System.out.println(file.getPath()); // dir1\dir2\aaa.txt
System.out.println(file.getName()); // aaa.txt
System.out.println(file.getParent()); // dir1\dir2

File getParentFile ()

Returns the abstract pathname of this abstract pathname's parent, or null if this pathname does not name a parent directory.

final var file = new File("dir1\\dir2\\aaa.txt");
System.out.println(file); // dir1\dir2\aaa.txt

final var parent = file.getParentFile();
System.out.println(parent); // dir1\dir2

final var parentParent = parent.getParentFile();
System.out.println(parentParent); // dir1

String getPath ()

Converts this abstract pathname into a pathname string.

final var file = new File("dir1\\dir2\\aaa.txt");

System.out.println(file.getPath()); // dir1\dir2\aaa.txt
System.out.println(file.getName()); // aaa.txt
System.out.println(file.getParent()); // dir1\dir2

long getTotalSpace ()

Returns the size of the partition named by this abstract pathname.

final var file = new File("D:");
System.out.println(file); // D:

// --- PowerShell ---
//PS R:\java-work> Get-PSDrive D
//
//Name           Used (GB)     Free (GB) Provider      Root ...
//----           ---------     --------- --------      ---- ...
//D                1665.41        197.48 FileSystem    D:\  ...

System.out.println(file.getTotalSpace()); // 2000263573504
System.out.println(file.getFreeSpace()); // 212039778304
System.out.println(file.getUsableSpace()); // 212039778304

long getUsableSpace ()

Returns the number of bytes available to this virtual machine on the partition named by this abstract pathname.

final var file = new File("D:");
System.out.println(file); // D:

// --- PowerShell ---
//PS R:\java-work> Get-PSDrive D
//
//Name           Used (GB)     Free (GB) Provider      Root ...
//----           ---------     --------- --------      ---- ...
//D                1665.41        197.48 FileSystem    D:\  ...

System.out.println(file.getTotalSpace()); // 2000263573504
System.out.println(file.getFreeSpace()); // 212039778304
System.out.println(file.getUsableSpace()); // 212039778304

int hashCode ()

Computes a hash code for this abstract pathname.

final var os = System.getProperty("os.name");
System.out.println(os); // Windows 10

// A path name on Windows is not case-sensitive.
final var ret1 = new File("aaa.txt").hashCode();
System.out.println(ret1); // -1239232814

final var ret2 = new File("AAA.TXT").hashCode();
System.out.println(ret2); // -1239232814

final var ret1 = new File("dir1\\dir2\\aaa.txt").hashCode();
System.out.println(ret1); // -639828267

final var ret2 = new File("R:\\java-work\\aaa.txt").hashCode();
System.out.println(ret2); // 503453694

boolean isAbsolute ()

Tests whether this abstract pathname is absolute.

public class Main {

    public static void main(String[] args) throws IOException {

        final var userDir = System.getProperty("user.dir");
        System.out.println("user.dir = " + userDir);

        {
            final var file = new File("aaa.txt");

            System.out.println("------");
            System.out.println("file = " + file);
            System.out.println("isAbsolute = " + file.isAbsolute());
            System.out.println("getAbsoluteFile = " + file.getAbsoluteFile());
            System.out.println("getAbsolutePath = " + file.getAbsolutePath());
        }
        {
            final var file = new File("R:\\java-work\\bbb.txt");

            System.out.println("------");
            System.out.println("file = " + file);
            System.out.println("isAbsolute = " + file.isAbsolute());
            System.out.println("getAbsoluteFile = " + file.getAbsoluteFile());
            System.out.println("getAbsolutePath = " + file.getAbsolutePath());
        }
    }
}

// --- PowerShell ---
//PS R:\java-work> java Main.java
//user.dir = R:\java-work
//------
//file = aaa.txt
//isAbsolute = false
//getAbsoluteFile = R:\java-work\aaa.txt
//getAbsolutePath = R:\java-work\aaa.txt
//------
//file = R:\java-work\bbb.txt
//isAbsolute = true
//getAbsoluteFile = R:\java-work\bbb.txt
//getAbsolutePath = R:\java-work\bbb.txt

boolean isDirectory ()

Tests whether the file denoted by this abstract pathname is a directory.

final var file = new File("R:\\java-work\\aaa.txt");
System.out.println(file); // R:\java-work\aaa.txt

final var dir = new File("R:\\java-work\\dir");
System.out.println(dir); // R:\java-work\dir

final var nonExistentPath = new File("R:\\java-work\\xxx");
System.out.println(nonExistentPath); // R:\java-work\xxx

System.out.println(file.createNewFile()); // true
System.out.println(dir.mkdir()); // true

// --- PowerShell ---
//PS R:\java-work> ls | Format-Table -Property Mode, Name
//
//Mode  Name
//----  ----
//d---- dir
//-a--- aaa.txt

System.out.println(file.isFile()); // true
System.out.println(file.isDirectory()); // false
System.out.println(file.exists()); // true

System.out.println(dir.isFile()); // false
System.out.println(dir.isDirectory()); // true
System.out.println(dir.exists()); // true

System.out.println(nonExistentPath.isFile()); // false
System.out.println(nonExistentPath.isDirectory()); // false
System.out.println(nonExistentPath.exists()); // false

boolean isFile ()

Tests whether the file denoted by this abstract pathname is a normal file.

final var file = new File("R:\\java-work\\aaa.txt");
System.out.println(file); // R:\java-work\aaa.txt

final var dir = new File("R:\\java-work\\dir");
System.out.println(dir); // R:\java-work\dir

final var nonExistentPath = new File("R:\\java-work\\xxx");
System.out.println(nonExistentPath); // R:\java-work\xxx

System.out.println(file.createNewFile()); // true
System.out.println(dir.mkdir()); // true

// --- PowerShell ---
//PS R:\java-work> ls | Format-Table -Property Mode, Name
//
//Mode  Name
//----  ----
//d---- dir
//-a--- aaa.txt

System.out.println(file.isFile()); // true
System.out.println(file.isDirectory()); // false
System.out.println(file.exists()); // true

System.out.println(dir.isFile()); // false
System.out.println(dir.isDirectory()); // true
System.out.println(dir.exists()); // true

System.out.println(nonExistentPath.isFile()); // false
System.out.println(nonExistentPath.isDirectory()); // false
System.out.println(nonExistentPath.exists()); // false

boolean isHidden ()

Tests whether the file named by this abstract pathname is a hidden file.

final var file = new File("R:\\java-work\\aaa.txt");
System.out.println(file); // R:\java-work\aaa.txt
System.out.println(file.createNewFile()); // true

System.out.println(file.isHidden()); // false

// --- PowerShell ---
//PS R:\java-work> ls -Force | Format-Table -Property Mode, Name
//
//Mode  Name
//----  ----
//-a--- aaa.txt

Files.setAttribute(file.toPath(), "dos:hidden", true);

System.out.println(file.isHidden()); // true

// --- PowerShell ---
//PS R:\java-work> ls -Force | Format-Table -Property Mode, Name
//
//Mode  Name
//----  ----
//-a-h- aaa.txt

long lastModified ()

Returns the time that the file denoted by this abstract pathname was last modified.

final var file = new File("R:\\java-work\\aaa.txt");
System.out.println(file); // R:\java-work\aaa.txt
System.out.println(file.createNewFile()); // true

final var zoneId = ZoneId.systemDefault();
System.out.println(zoneId); // Asia/Tokyo

final var dateTime1 = ZonedDateTime.of(2100, 1, 1, 0, 0, 0, 0, zoneId);
System.out.println(dateTime1); // 2100-01-01T00:00+09:00[Asia/Tokyo]

final var ret = file.setLastModified(dateTime1.toInstant().toEpochMilli());
System.out.println(ret); // true

// --- PowerShell ---
//PS R:\java-work> ls | Format-Table -Property LastWriteTime, Name
//
//LastWriteTime      Name
//-------------      ----
//2100/01/01 0:00:00 aaa.txt

final var lastModified = file.lastModified();
System.out.println(lastModified); // 4102412400000

final var dateTime2 = ZonedDateTime.ofInstant(
        Instant.ofEpochMilli(lastModified), zoneId);
System.out.println(dateTime2); // 2100-01-01T00:00+09:00[Asia/Tokyo]

long length ()

Returns the length of the file denoted by this abstract pathname.

// --- PowerShell ---
//PS R:\java-work> tree /F
//...
//R:.
//│  aaa.txt
//│  bbb.txt
//│
//└─dir
//        ccc.txt
//
//PS R:\java-work> ls | Format-Table -Property Length, Name
//
//Length Name
//------ ----
//       dir
//5      aaa.txt
//1000   bbb.txt
//
//PS R:\java-work> ls dir | Format-Table -Property Length, Name
//
//Length Name
//------ ----
//    12 ccc.txt

final var file1 = new File("R:\\java-work\\aaa.txt");
System.out.println(file1); // R:\java-work\aaa.txt
System.out.println(file1.length()); // 5

final var file2 = new File("R:\\java-work\\bbb.txt");
System.out.println(file2); // R:\java-work\bbb.txt
System.out.println(file2.length()); // 1000

final var dir = new File("R:\\java-work\\dir");
System.out.println(dir); // R:\java-work\dir
System.out.println(dir.length()); // 0

String[] list ()

Returns an array of strings naming the files and directories in the directory denoted by this abstract pathname.

// --- PowerShell ---
//PS R:\java-work> tree /F
//...
//R:.
//│  aaa.txt
//│  bbb.txt
//│
//└─dir
//        ccc.txt
//        ddd.txt

{
    final var dir = new File("R:\\java-work");
    System.out.println(dir); // R:\java-work

    final var ret = dir.list();
    System.out.println(Arrays.toString(ret)); // [aaa.txt, bbb.txt, dir]
}
{
    final var dir = new File("R:\\java-work\\dir");
    System.out.println(dir); // R:\java-work\dir

    final var ret = dir.list();
    System.out.println(Arrays.toString(ret)); // [ccc.txt, ddd.txt]
}

String[] list (FilenameFilter filter)

Returns an array of strings naming the files and directories in the directory denoted by this abstract pathname that satisfy the specified filter.

// --- PowerShell ---
//PS R:\java-work> ls -Name
//aaa.txt
//bbb.jpg
//ccc.txt
//ddd.jpg

final var dir = new File("R:\\java-work");
System.out.println(dir); // R:\java-work

final var filter = new FilenameFilter() {
    @Override
    public boolean accept(File dir, String name) {
        return name.endsWith(".txt");
    }
};

final var ret1 = dir.list();
System.out.println(Arrays.toString(ret1)); // [aaa.txt, bbb.jpg, ccc.txt, ddd.jpg]

final var ret2 = dir.list(filter);
System.out.println(Arrays.toString(ret2)); // [aaa.txt, ccc.txt]

File[] listFiles ()

Returns an array of abstract pathnames denoting the files in the directory denoted by this abstract pathname.

// --- PowerShell ---
//PS R:\java-work> tree /F
//...
//R:.
//│  aaa.txt
//│  bbb.txt
//│
//└─dir
//        ccc.txt
//        ddd.txt

{
    final var dir = new File("R:\\java-work");
    System.out.println(dir); // R:\java-work

    final var files = dir.listFiles();
    if (files != null) {
        System.out.println("-- listFiles --");
        for (final var file : files) {
            System.out.println(file);
        }
    }

    // Result
    // ↓
    //-- listFiles --
    //R:\java-work\aaa.txt
    //R:\java-work\bbb.txt
    //R:\java-work\dir
}
{
    final var dir = new File("R:\\java-work\\dir");
    System.out.println(dir); // R:\java-work\dir

    final var files = dir.listFiles();
    if (files != null) {
        System.out.println("-- listFiles --");
        for (final var file : files) {
            System.out.println(file);
        }
    }

    // Result
    // ↓
    //-- listFiles --
    //R:\java-work\dir\ccc.txt
    //R:\java-work\dir\ddd.txt
}

File[] listFiles (FileFilter filter)

Returns an array of abstract pathnames denoting the files and directories in the directory denoted by this abstract pathname that satisfy the specified filter.

// --- PowerShell ---
//PS R:\java-work> ls -Name
//aaa.txt
//bbb.jpg
//ccc.txt
//ddd.jpg

final var dir = new File("R:\\java-work");
System.out.println(dir); // R:\java-work

final var filter = new FileFilter() {
    @Override
    public boolean accept(File pathname) {
        return pathname.getName().endsWith(".txt");
    }
};

final var files = dir.listFiles(filter);
if (files != null) {
    System.out.println("-- listFiles --");
    for (final var file : files) {
        System.out.println(file);
    }
}

// Result
// ↓
//-- listFiles --
//R:\java-work\aaa.txt
//R:\java-work\ccc.txt

File[] listFiles (FilenameFilter filter)

Returns an array of abstract pathnames denoting the files and directories in the directory denoted by this abstract pathname that satisfy the specified filter.

// --- PowerShell ---
//PS R:\java-work> ls -Name
//aaa.txt
//bbb.jpg
//ccc.txt
//ddd.jpg

final var dir = new File("R:\\java-work");
System.out.println(dir); // R:\java-work

final var filter = new FilenameFilter() {
    @Override
    public boolean accept(File dir, String name) {
        return name.endsWith(".txt");
    }
};

final var files = dir.listFiles(filter);
if (files != null) {
    System.out.println("-- listFiles --");
    for (final var file : files) {
        System.out.println(file);
    }
}

// Result
// ↓
//-- listFiles --
//R:\java-work\aaa.txt
//R:\java-work\ccc.txt

static File[] listRoots ()

List the available filesystem roots.

final var roots = File.listRoots();
for (final var root : roots) {
    System.out.println(root);
}

// Result
// ↓
//C:\
//D:\
//...

boolean mkdir ()

Creates the directory named by this abstract pathname.

// --- PowerShell ---
//PS R:\java-work> ls -Name
//<No files / directories>

final var dir1 = new File("R:\\java-work\\dir1");
System.out.println(dir1); // R:\java-work\dir1

System.out.println(dir1.mkdir()); // true

// --- PowerShell ---
//PS R:\java-work> tree /F
//...
//R:.
//└─dir1

final var dir2 = new File(dir1, "dir2");
System.out.println(dir2); // R:\java-work\dir1\dir2

System.out.println(dir2.mkdir()); // true

// --- PowerShell ---
//PS R:\java-work> tree /F
//...
//R:.
//└─dir1
//    └─dir2

// --- PowerShell ---
//PS R:\java-work> ls -Name
//<No files / directories>

final var dir = new File("R:\\java-work\\dir1\\dir2");
System.out.println(dir); // R:\java-work\dir1\dir2

System.out.println(dir.mkdir()); // false

// --- PowerShell ---
//PS R:\java-work> ls -Name
//<No files / directories>

boolean mkdirs ()

Creates the directory named by this abstract pathname, including any necessary but nonexistent parent directories.

// --- PowerShell ---
//PS R:\java-work> ls -Name
//<No files / directories>

final var dir = new File("R:\\java-work\\dir1\\dir2");
System.out.println(dir); // R:\java-work\dir1\dir2

System.out.println(dir.mkdirs()); // true

// --- PowerShell ---
//PS R:\java-work> tree /F
//...
//R:.
//└─dir1
//    └─dir2

boolean renameTo (File dest)

Renames the file denoted by this abstract pathname.

final var src = new File("R:\\java-work\\src.txt");
System.out.println(src); // R:\java-work\src.txt

final var dst = new File("R:\\java-work\\dst.txt");
System.out.println(dst); // R:\java-work\dst.txt

System.out.println(src.exists()); // true
System.out.println(dst.exists()); // false

// --- PowerShell ---
//PS R:\java-work> ls -Name
//src.txt
//PS R:\java-work> cat src.txt
//abcd

System.out.println(src.renameTo(dst)); // true

System.out.println(src.exists()); // false
System.out.println(dst.exists()); // true

// --- PowerShell ---
//PS R:\java-work> ls -Name
//dst.txt
//PS R:\java-work> cat dst.txt
//abcd

boolean setExecutable (boolean executable)

A convenience method to set the owner's execute permission for this abstract pathname.

// --- Linux Terminal ---
//$ touch sample1.sh
//$ ls -l sample1.sh
//-rw-rw-r-- 1 xxxx xxxx 0 ... sample1.sh

final var os = System.getProperty("os.name");
System.out.println(os); // Linux

final var file = new File("sample1.sh");
System.out.println(file); // sample1.sh

System.out.println(file.canExecute()); // false
System.out.println(file.setExecutable(true)); // true

System.out.println(file.canExecute()); // true

// --- Linux Terminal ---
//$ ls -l sample1.sh
//-rwxrw-r-- 1 xxxx xxxx 0 ... sample1.sh

// --- Linux Terminal ---
//$ touch sample2.sh
//$ ls -l sample2.sh
//-rw-rw-r-- 1 xxxx xxxx 0 ... sample2.sh

final var file = new File("sample2.sh");
System.out.println(file); // sample2.sh

System.out.println(file.canExecute()); // false
System.out.println(file.setExecutable(true, false)); // true

System.out.println(file.canExecute()); // true

// --- Linux Terminal ---
//$ ls -l sample2.sh
//-rwxrwxr-x 1 xxxx xxxx 0 ... sample2.sh

boolean setExecutable (boolean executable, boolean ownerOnly)

Sets the owner's or everybody's execute permission for this abstract pathname.

// --- Linux Terminal ---
//$ touch sample1.sh
//$ ls -l sample1.sh
//-rw-rw-r-- 1 xxxx xxxx 0 ... sample1.sh

final var os = System.getProperty("os.name");
System.out.println(os); // Linux

final var file = new File("sample1.sh");
System.out.println(file); // sample1.sh

System.out.println(file.canExecute()); // false
System.out.println(file.setExecutable(true)); // true

System.out.println(file.canExecute()); // true

// --- Linux Terminal ---
//$ ls -l sample1.sh
//-rwxrw-r-- 1 xxxx xxxx 0 ... sample1.sh

// --- Linux Terminal ---
//$ touch sample2.sh
//$ ls -l sample2.sh
//-rw-rw-r-- 1 xxxx xxxx 0 ... sample2.sh

final var file = new File("sample2.sh");
System.out.println(file); // sample2.sh

System.out.println(file.canExecute()); // false
System.out.println(file.setExecutable(true, false)); // true

System.out.println(file.canExecute()); // true

// --- Linux Terminal ---
//$ ls -l sample2.sh
//-rwxrwxr-x 1 xxxx xxxx 0 ... sample2.sh

boolean setLastModified (long time)

Sets the last-modified time of the file or directory named by this abstract pathname.

final var file = new File("R:\\java-work\\aaa.txt");
System.out.println(file); // R:\java-work\aaa.txt
System.out.println(file.createNewFile()); // true

final var zoneId = ZoneId.systemDefault();
System.out.println(zoneId); // Asia/Tokyo

final var dateTime1 = ZonedDateTime.of(2100, 1, 1, 0, 0, 0, 0, zoneId);
System.out.println(dateTime1); // 2100-01-01T00:00+09:00[Asia/Tokyo]

final var ret = file.setLastModified(dateTime1.toInstant().toEpochMilli());
System.out.println(ret); // true

// --- PowerShell ---
//PS R:\java-work> ls | Format-Table -Property LastWriteTime, Name
//
//LastWriteTime      Name
//-------------      ----
//2100/01/01 0:00:00 aaa.txt

final var lastModified = file.lastModified();
System.out.println(lastModified); // 4102412400000

final var dateTime2 = ZonedDateTime.ofInstant(
        Instant.ofEpochMilli(lastModified), zoneId);
System.out.println(dateTime2); // 2100-01-01T00:00+09:00[Asia/Tokyo]

boolean setReadable (boolean readable)

A convenience method to set the owner's read permission for this abstract pathname.

// --- Linux Terminal ---
//$ touch sample1.txt
//$ ls -l sample1.txt
//-rw-rw-r-- 1 xxxx xxxx 0 ... sample1.txt

final var os = System.getProperty("os.name");
System.out.println(os); // Linux

final var file = new File("sample1.txt");
System.out.println(file); // sample1.txt

System.out.println(file.canRead()); // true
System.out.println(file.setReadable(false)); // true

System.out.println(file.canRead()); // false

// --- Linux Terminal ---
//$ ls -l sample1.txt
//--w-rw-r-- 1 xxxx xxxx 0 ... sample1.txt

// --- Linux Terminal ---
//$ touch sample2.txt
//$ ls -l sample2.txt
//-rw-rw-r-- 1 xxxx xxxx 0 ... sample2.txt

final var file = new File("sample2.txt");
System.out.println(file); // sample2.txt

System.out.println(file.canRead()); // true
System.out.println(file.setReadable(false, false)); // true

System.out.println(file.canRead()); // false

// --- Linux Terminal ---
//$ ls -l sample2.txt
//--w--w---- 1 xxxx xxxx 0 ... sample2.txt

boolean setReadable (boolean readable, boolean ownerOnly)

Sets the owner's or everybody's read permission for this abstract pathname.

// --- Linux Terminal ---
//$ touch sample1.txt
//$ ls -l sample1.txt
//-rw-rw-r-- 1 xxxx xxxx 0 ... sample1.txt

final var os = System.getProperty("os.name");
System.out.println(os); // Linux

final var file = new File("sample1.txt");
System.out.println(file); // sample1.txt

System.out.println(file.canRead()); // true
System.out.println(file.setReadable(false)); // true

System.out.println(file.canRead()); // false

// --- Linux Terminal ---
//$ ls -l sample1.txt
//--w-rw-r-- 1 xxxx xxxx 0 ... sample1.txt

// --- Linux Terminal ---
//$ touch sample2.txt
//$ ls -l sample2.txt
//-rw-rw-r-- 1 xxxx xxxx 0 ... sample2.txt

final var file = new File("sample2.txt");
System.out.println(file); // sample2.txt

System.out.println(file.canRead()); // true
System.out.println(file.setReadable(false, false)); // true

System.out.println(file.canRead()); // false

// --- Linux Terminal ---
//$ ls -l sample2.txt
//--w--w---- 1 xxxx xxxx 0 ... sample2.txt

boolean setReadOnly ()

Marks the file or directory named by this abstract pathname so that only read operations are allowed.

final var file = new File("R:\\java-work\\aaa.txt");
System.out.println(file); // R:\java-work\aaa.txt
System.out.println(file.createNewFile()); // true

// --- PowerShell ---
//PS R:\java-work> ls | Format-Table -Property Mode, Name
//
//Mode  Name
//----  ----
//-a--- aaa.txt

System.out.println(file.setReadOnly()); // true

// --- PowerShell ---
//PS R:\java-work> ls | Format-Table -Property Mode, Name
//
//Mode  Name
//----  ----
//-ar-- aaa.txt

boolean setWritable (boolean writable)

A convenience method to set the owner's write permission for this abstract pathname.

// --- Linux Terminal ---
//$ touch sample1.txt
//$ ls -l sample1.txt
//-rw-rw-r-- 1 xxxx xxxx 0 ... sample1.txt

final var os = System.getProperty("os.name");
System.out.println(os); // Linux

final var file = new File("sample1.txt");
System.out.println(file); // sample1.txt

System.out.println(file.canWrite()); // true
System.out.println(file.setWritable(false)); // true

System.out.println(file.canWrite()); // false

// --- Linux Terminal ---
//$ ls -l sample1.txt
//-r--rw-r-- 1 xxxx xxxx 0 ... sample1.txt

// --- Linux Terminal ---
//$ touch sample2.txt
//$ ls -l sample2.txt
//-rw-rw-r-- 1 xxxx xxxx 0 ... sample2.txt

final var file = new File("sample2.txt");
System.out.println(file); // sample2.txt

System.out.println(file.canWrite()); // true
System.out.println(file.setWritable(false, false)); // true

System.out.println(file.canWrite()); // false

// --- Linux Terminal ---
//$ ls -l sample2.txt
//-r--r--r-- 1 xxxx xxxx 0 ... sample2.txt

boolean setWritable (boolean writable, boolean ownerOnly)

Sets the owner's or everybody's write permission for this abstract pathname.

// --- Linux Terminal ---
//$ touch sample1.txt
//$ ls -l sample1.txt
//-rw-rw-r-- 1 xxxx xxxx 0 ... sample1.txt

final var os = System.getProperty("os.name");
System.out.println(os); // Linux

final var file = new File("sample1.txt");
System.out.println(file); // sample1.txt

System.out.println(file.canWrite()); // true
System.out.println(file.setWritable(false)); // true

System.out.println(file.canWrite()); // false

// --- Linux Terminal ---
//$ ls -l sample1.txt
//-r--rw-r-- 1 xxxx xxxx 0 ... sample1.txt

// --- Linux Terminal ---
//$ touch sample2.txt
//$ ls -l sample2.txt
//-rw-rw-r-- 1 xxxx xxxx 0 ... sample2.txt

final var file = new File("sample2.txt");
System.out.println(file); // sample2.txt

System.out.println(file.canWrite()); // true
System.out.println(file.setWritable(false, false)); // true

System.out.println(file.canWrite()); // false

// --- Linux Terminal ---
//$ ls -l sample2.txt
//-r--r--r-- 1 xxxx xxxx 0 ... sample2.txt

Path toPath ()

Returns a java.nio.file.Path object constructed from this abstract path.

final var file = new File("R:\\java-work\\aaa.txt");
System.out.println(file); // R:\java-work\aaa.txt

final var path = file.toPath();
System.out.println(path); // R:\java-work\aaa.txt

Files.writeString(path, "abcd");

// --- PowerShell ---
//PS R:\java-work> ls -Name
//aaa.txt
//PS R:\java-work> cat aaa.txt
//abcd

String toString ()

Returns the pathname string of this abstract pathname.

final var file = new File("aaa.txt");
final var str = file.toString();
System.out.println(str); // aaa.txt

final var dir = new File("R:\\java-work\\dir");
final var str = dir.toString();
System.out.println(str); // R:\java-work\dir

URI toURI ()

Constructs a file: URI that represents this abstract pathname.

final var file = new File("R:\\java-work\\aaa.txt");
System.out.println(file); // R:\java-work\aaa.txt

final var uri = file.toURI();
System.out.println(uri); // file:/R:/java-work/aaa.txt

URL toURL ()

Deprecated. This method does not automatically escape characters that are illegal in URLs.

Deprecated.

API Examples

Java : File with Examples

Summary

Fields

static final String pathSeparator

static final char pathSeparatorChar

static final String separator

static final char separatorChar

Constructors

File (File parent, String child)

File (String pathname)

File (String parent, String child)

File (URI uri)

Methods

boolean canExecute ()

boolean canRead ()

boolean canWrite ()

int compareTo (File pathname)

boolean createNewFile ()

static File createTempFile (String prefix, String suffix)

static File createTempFile (String prefix, String suffix, File directory)

boolean delete ()

void deleteOnExit ()

boolean equals (Object obj)

boolean exists ()

File getAbsoluteFile ()

String getAbsolutePath ()

File getCanonicalFile ()

String getCanonicalPath ()

long getFreeSpace ()

String getName ()

String getParent ()

File getParentFile ()

String getPath ()

long getTotalSpace ()

long getUsableSpace ()

int hashCode ()

boolean isAbsolute ()

boolean isDirectory ()

boolean isFile ()

boolean isHidden ()

long lastModified ()

long length ()

String[] list ()

String[] list (FilenameFilter filter)

File[] listFiles ()

File[] listFiles (FileFilter filter)

File[] listFiles (FilenameFilter filter)

static File[] listRoots ()

boolean mkdir ()

boolean mkdirs ()

boolean renameTo (File dest)

boolean setExecutable (boolean executable)

boolean setExecutable (boolean executable, boolean ownerOnly)

boolean setLastModified (long time)

boolean setReadable (boolean readable)

boolean setReadable (boolean readable, boolean ownerOnly)

boolean setReadOnly ()

boolean setWritable (boolean writable)

boolean setWritable (boolean writable, boolean ownerOnly)

Path toPath ()

String toString ()

URI toURI ()

URL toURL ()

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